Daniel Pratt Mannix IV was best known as an American author and journalist. His life was remarkably different from other writers of his generation. His career included times as a side show performer, magician, trainer of eagles and film maker.
The Grest Zadma was a stage name Mannix used as a magician. He also entertained as a sword swallower and fire eater in a traveling carnival sideshow. Magazine articles about these experiences, co-written with his wife, became very popular in 1944 and 1945.
As an author Mannix covered a wide variety of subject matter. His more than 25 books ranged from fictional animal stories for children, the natural history of animals, and adventurous accounts about hunting big game to sensational adult non-fiction topics such as a biography of the occultist Aleister Crowley, sympathetic accounts of carnival performers and sideshow freaks, and works describing, among other things, the Hellfire Club, the Atlantic slave trade, the history of torture, and the Roman games. His output of essays and articles was extensive.